JLG 400CRT ANSI Service Manual - Manual (Page 47)

SECTION 3 - TROUBLESHOOTING
3121111 – JLG Lift – 3-5
Loose or damaged wiring between drive
controller and High Speed switch. Ensure proper connection of wires. Using
suitable test meter, perform continuity test
on wiring between switches. Repair or
replace wires as necessary.
Defective high speed control switch. Replace high speed control switch.
Loose or damaged wiring in control box
wire harness. Ensure proper connection of wires at the
control switch. Using suitable test meter,
perform continuity test on wires. Repair or
replace harness as necessary.
Loose or damaged wiring between plat-
form and high speed solenoid. Ensure proper connection of wires at the
platform and at the high speed solenoid.
Using suitable test meter, perform conti-
nuity test on wires. Repair or replace
wires as necessary.
High speed solenoid not functioning
properly. Replace solenoid.
Loose or damaged wiring between high
speed relay and high speed limit switch. Ensure proper connection of wires
between high speed relay and high speed
limit switch. Using suitable test meter, per-
form continuity test on wires. Repair or
replace wires as necessary.
High speed limit switch not functioning
properly. Repair or replace limit switch.
Loose or damaged wiring in valve wiring
harness. Ensure proper connection of wires at ter-
minal strip. Using suitable test meter, per-
form continuity test on wires. Repair or
replace wires as necessary.
Steering System
No response to steer control switch on controller
Steer switch on controller not functioning
properly. Repair or replace switch.
Hydraulic system oil low. Replenish oil as necessary.
Hydraulic system pressure too low. Adjust pressure.
Loose or damaged wiring on control
switch or solenoid valve. Ensure proper connection of wires at con-
trol switch or solenoid valve. Using suit-
able test meter, perform continuity test on
wires. Repair or replace wires as neces-
sary.
Restricted or broken hydraulic line on
valve bank or hydraulic pump. Clean, repair or replace line.
Control valve not functioning properly. Repair or replace valve.
Steer cylinder not functioning properly. Repair or replace cylinder.
Machine hard to steer or steering is erratic
Hydraulic system oil low. Replenish oil as necessary.
Restricted or broken hydraulic line or fit-
ting. Clean, repair or replace line or fitting.
Table 3-2. Chassis Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY